How We Observe the Ocean

Tropical Moored Buoys

The design for the Global Tropical Moored Buoy Array calls for 137 moorings blanketing the tropical regions of the world's oceans. The goal of the moored buoy program is to provide high quality moored time series and related data throughout the global tropics for improved description, understanding and prediction of seasonal to decadal time scale climate variability. Focus on the tropics is dictated by its role as a heat engine for the Earth’s climate system, engendering phenomena such as the El Niño/Southern Oscillation (ENSO), the monsoons, the Indian Ocean Dipole, and tropical Atlantic climate variability. In addition to monitoring the air-sea exchange of heat and water, the moored buoys provide platforms for instrumentation to measure solar and thermal radiation, as well as air-sea exchange of carbon dioxide in the tropics.

Observations near the equator are of particular importance to climate because most of the heat from the sun enters the ocean in the tropical/ sub-tropical belt. In addition to monitoring the air-sea exchange of heat and water, the moored buoys provide platforms for instrumentation to measure the air-sea exchange of carbon dioxide in the tropics.

Past understanding of the role of the tropics in forcing mid-latitude weather and climate has been garnered through the observations of the tropical moored buoy array in the Pacific Ocean, TAO/TRITON (Tropical Atmosphere Ocean/Triangle Trans-Ocean Buoy Network), which now comprises 72 moorings.

A similar array of 18 moorings in the Atlantic basin, PIRATA (Pilot Research Moored Array in the Tropical Atlantic) is further improving forecasting capabilities and is elucidating causes of longer-term changes in the ocean. The partially-completed Indian Ocean array, RAMA (Research Moored Array for African- Asian-Australian Monsoon Analysis and Prediction), whose system design calls for 46 moorings, will complete global coverage of the Earth’s tropical oceans.

The TAO array in the Pacific Ocean is operated (under separate management, by the NOAA National Data Buoy Center) in cooperations with The Japan Agency for Marine-Earth Science and Technology (JAMSTEC), which operates the Triangle Trans-Ocean Buoy Network (TRITON) of buoys in the western Pacific. The PIRATA array in the Atlantic is operated by NOAA in cooperation with Brazil and France; the RAMA array in the Indian Ocean is operated by NOAA in cooperation with Japan, France, India, Indonesia, China, and a consortium of nine African nations participating in the Agulhas and Somali Current Large Marine Ecosystem Project.